The invention relates to a semiconductor device and a method of manufacturing the same.
In recent years, with miniaturization of an ultralarge-scale integration (ULSI), miniaturization of an interconnect has been progressed. Therefore, an increase in an inter-interconnect capacitance may be a problem, and thereby the lowering of a dielectric constant in an insulating interlayer has been progressed. As technologies for forming an interconnect in the insulating film having a low dielectric constant, technologies described in WO 2007-132879 and Japanese Unexamined Patent Application Publication No. 2009-289996 may be exemplified.
In WO 2007-132879, there is disclosed that a modified layer, in which the number of carbon atoms per unit volume is smaller than that inside the insulating film and the number of oxygen atoms per unit volume is larger than that inside the insulating film, is formed in an interface between the insulating film and a metal, or the like. In WO 2007-132879, it is disclosed that such a modified layer is formed, such that the modified layer may become thin and have a superior insulation property, and it is possible to reduce an interconnect leakage current while maintaining a low inter-interconnect capacitance.
In addition, in Japanese Unexamined Patent Application Publication No. 2009-289996, it is disclosed that the insulating film having a low dielectric constant has a small mechanical strength, such that cracks may occur in the insulating interlayer or the insulating interlayer may be peeled off in a process which a large stress occurs among the processes of manufacturing the semiconductor device, such as a chemical mechanical polishing (CMP) or a packaging process. Here, in Japanese Unexamined Patent Application Publication No. 2009-289996, a SiOC film, which includes a skeleton structure portion containing SiOC and a pore forming material portion containing a hydrocarbon compound, is formed over a substrate, and the SiOC film is irradiated with light having a wavelength equal to or larger than 200 nm and equal to or smaller than 260 nm, such that when the SiOC film is irradiated with light, a three-membered ring Si—O coupling (referred to as a “six-membered ring structure” in the summary of the invention described later) or a Si—H coupling is not generated, and on the other hand, a network Si—O coupling is increased, whereby it is possible to increase the mechanical strength of the SiOC film and it is possible to avoid the deterioration in resistance to process damage.